Try resetting your router and testing your connection to reset everything.

Hopefully that helps...

Actually, try looking for updates with the game out of the system... "System Updates"? I forget exactly what it says. But, try updating without the game in. It could be a very simple fix. Let me know if that works!

I have this problem occasionally here is what I've done to fix it.

If you have auto-sign to in to PSN turned on turn it off and then restart your PS3. When the system restarts open the game and wait to be prompted to download. Hopefully it will work at this point if not hit cancel and sign in to PSN manually then try again. If that doesn't work send me a message on PSN and I'll see if I can help you. (I do tech support for a living, thankfully I won't charge you what I normally get paid :) )

PSN: SaiKing

Hope to see you online.

I have the exact same problem as jmiguel. I've already tried all the solutions that you guys have provided but it still won't work. Are there any others with the same problems? Any other solutions? Please kindly advise.